<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="js/vue.min.js"> </script>
</head>
<body>
<div id="app">

    <h3 v-if="true" id="a1"> 百知教育</h3>
    <h3 v-if="false" id=" "> 百知教育</h3>
    <h3 v-else id="a2">欢迎你</h3>
    <h3 v-else-if="false">加入</h3>

</div>
<script>
    new Vue({
        el: '#app',
        data: {},

    })
</script>
</body>
</html>